1. Field of the Invention
The present invention relates generally to geometrical instruments and more specifically, to cylinder lock tumbler decoders and a method of using the same. The present invention also relates generally to locks and in particular, to picks keys for picking the operating elements of the operating mechanism of a lock.
2. Description of the Prior Art
For years locksmiths have spent an hour or longer trying to open or make an impression for a key in an ignition lock on the steering column of automobiles manufactured by General Motors of the United States. It has been said that these ignition locks cannot be picked and if the same could be picked, there is no way to decode the tumblers in the unlocked position. The present invention enables one skilled in the art of locksmithing to pick and decode ignition locks manufactured by General Motors of the United States.
Various types of tool sets and methods of decoding locks are known in the prior art. An example of such tool is found in U.S. Pat. No. 3,827,151 issued on Aug. 6, 1974 to Nail. This patent discloses a decoding instrument for a pin-type tumbler lock. The instrument includes a frame having a decoder support for a plurality of shim-like, toothed decoders, where the combined thickness of the support and decoders is less than the width of the key-receiving slot in the barrel of a lock. The decoders are shiftable independently of one another and longitudinally of the support to detect the individual movement of the pins. The frame includes indicia which, in combination with the movements of the decoders, can indicate the extent of movements of the pins that is necessary to release the barrel for movement relative to the lock-body.
In the Nail patent, decoding is effected by shifting the decoders separately. Each individual decoder is provided with a single tooth. The decoder support and the five decoders are inserted in the barrel through the slot of the lock. Then all levers are shifted to the right, at which position they will engage a screw and will register with the numeral 5. Then one of the levers is shifted to the left whereby the ramp on the tooth inserted the farthest moves the deepest pin upwardly. This movement is continued until resistance to further movement is encountered due to the fact that the deepest pin is being pushed by the tooth into engagement with the inner margin of the lock body. This is known as the condition of resistance to movement of the pin. This resistance can be felt by the operator and the operator is then aware that the pin is moved to the margin. The lever which was shifted to the left is maintained in that position and thereafter each of the other levers is shifted to the left individually until they each encounter resistance. When this process is completed, the instrument can now be turned. The decoder can then be withdrawn and a record is made of the positions of the levers with respect to the indicia (numerals) on the extension. Having the data, as indicated by the positions of the levers with respect to the indicia, the exact depths can be cut in a key blank.
An alternative lock decoding mechanism is found in U.S. Pat. No. 4,185,482 issued Jan. 29, 1980 to Nail. The Nail patent discusses the use of a mechanism for opening and/or decoding the biddings of a key for opening a cylinder lock employing wafer type tumblers. The Nail device can be used for opening such locks when a key is lost. The lock mechanism disclosed in the Nail patent has only five (5) wafer type tumblers whereas modern lock mechanisms as used in General Motors automobiles employ six (6) tumblers with a fixed spacing along the longitudinal axis of the lock mechanism, but only five (5) different tumbler positions.
U.S. Pat. No. 4,667,494 issued on May 26, 1987 to Joosten discusses the use of a tool set and a method of opening and decoding a side bar lock employing wafer type tumblers. In the Joosten patent, a spring compressor tool configured for insertion into the lock mechanism keyway raises all the tumblers to a radially outward position and compresses the springs that normally bias the tumblers inwardly. A spring retainer tool inserted into the keyway with the spring compressor tool engages the tumbler springs to retain the springs in a compressed position but frees the tumblers for movement. The tumbler adjusting tool is inserted to grasp the tumblers, and move the tumblers to a position where the lock mechanism can be opened. A decoding tool is inserted to measure the radial position of each tumbler and provide a number which can be used to make a new key. A dust cover holding tool is provided to hold open the spring actuated dust cover.
While the above mentioned devices are appropriate for their intended usage, none of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.